Portable signalling device



IFune 24, 1958 c. E. G. REEVES PORTABLE SIGNALLING DEVICE 2 Sheets-Sheet1 Filed May 10, 1956 INVENTOR Cyaanss E. GEflflflM REEVES BY- fiaa M1,

ATTORNEYS June 24, 1958- r c. E. G. REEVES ,0 2

PORTABLE SIGNALLING DEVICE Filed May 10, 1956 2 Sheets-Sheet 2 INVENTORCHRLEZS zaxmm FE'EVES ATTORNEYS United States Patent PORTABLE SIGNALLINGDEVICE Charles E. Graham Reeves, Summit, N. J., assignor to Falcon AlarmCompany, Inc., a corporation of New Jersey Application May 10, 1956,Serial No. 584,138

3 Claims. (Cl. 116-112) The present invention relates to signallingdevices and relates, more particularly, to a self-powered, portablesignalling device.

The present application is a continuation-in-part of my copendingapplication Serial No. 516,090, filed June 17, 1955, now abandoned,entitled Portable Signalling Device.

An object of the invention is to provide self-contained, portablesignalling device employing a diaphragm type of horn which is small andinexpensive to manufacture, but which will produce a signal of'over 100decibels for a prolonged period of time when operated at relatively lowpressure from a container of vaporizable material such asdichlorodifluoromethane, more commonly known as Freon-l2 which in gas orvapor form has a density greater than air. Another object of theinvention is to provide a diaphragm type horn which uses a small diamteter diaphragm (less than 2 /2 inches) which may be operatedsatisfactorily by a gas of higher density than air.

A further object of the present invention is to provide an inexpensiveand efficient signalling device which is self-powered and which is lightenough to permit the device to be readily carried about by hand withoutdifiiculty. Another object of the invention is-to provide aself-powered, portable signalling device that will produce a loudaudible signal of considerable duration and which may be controlled asdesired by the operator.

A portable signalling device embodying the invention is especiallyuseful as an air raid signal or the like for civil defense purposes incase of power failures and in places where there are no existingsignalling systems or where the existing signalling systems cannot bereadily heard. In addition, such a signalling device is especiallyuseful for use as a horn on small boats and as an alarm for use inschools or other institutions. Further, the present invention provides asignalling device that does not require any electrical connections orthe like for its operation and is therefore safe for use underconditions where there is danger of explosion, as in oil refineries,mines or the like. In addition, the cost of a portable signalling deviceembodying the invention is much lower than when a conventionalsignalling device is used under such conditions.

Other objects and advantages of the invention will be apparent and bestunderstood from the following description and the accompanying drawings,in which:

Fig. 1 is a side elevation of a portable signalling device embodying theinvention;

Fig. 2 is an exploded view in section of the signalling deviceillustrated in Fig. 1, but on an enlarged scale; and

Fig. 3 is a vertical section view of the signalling device illustratedin Fig. 1, but on an enlarged scale.

Referring to the drawingsin detail, there is a cylinder ICC the supplyof vaporizable material is exhausted the cylinder may be replaced by theuser with a fresh cylinder.

Examples of vaporizable materials which will produce a gas having adensity greater than air are the fluorochloromethanes' (Freon). Suchmaterials may be maintained in liquid form at relatively low pressuresand hence may be'confined in relatively light cylinders or containers.(Freon12), 70 to 80 pounds pressure is sufiicient to maintain thematerial in liquid form at a normal temperature of 70 F.Dichlorodifluoromethane which has a boiling point of 29 C. (-2l.6 F.) atone atmosphere has been found to operate the signalling device attemperatures as low as 0 F. -In addition, a relatively small quantity ofsuch vaporizable material will supply sutficient gas or vapor at thepressure required to operate a signalling device of the characterdescribed herein for a considerable period of time. For example, it hasbeen found in actual use that a cylinder containing about 10 oz. ofdichlorodifiuoromethane (Freon-12) will produce a signal of over 100decibels for five or six minutes duration when operated continuously orapproximately three hundred two-second blasts when operatedintermittently.

A hexagonal fitting 11 is threaded into an opening in the top of thecylinder 10 and a sealing member 12 is clamped between the outside ofthe cylinder and a shoulder on the fitting. The fitting may be readilytightened with a wrench to prevent any leakage between the cylinder andthe fitting.

The fitting has a passageway 13 extending therethrough and a fine meshscreen 14 covers the lower end of the passageway toprevent solid matterfrom entering and possibly blocking the passageway. The upper end ofthefitting is threaded internally with a slight taper to receive a threadedend of a body 15 of a manually operable valve 16.

The manually operable valve 16 is of a type that is availablecommercially and need not be described in detail here. However, it willbe noted that the valve body 15 contains passageways 17, 18, and 19which provide communication between the passageway in the fitting andthe upper end of the valve body. One end of the passageway 18 opens intothe valve body and'the portion of the valve body surrounding suchopening is normally engaged by a resilient washer 20 under pressure froma spring 21 which closes the opening therein. The washer 20 is carriedon a plunger 22 which extends outside of the valve body. An operatinglever 23 is pivotally connected to the outer end of the plunger andbears against the outside of the valve body. The lever 23 when depressedor raised moves the washer away from the end of the passageway 18 andopens the valve so that the passageway 18 will be in communication withthe passageway 19.

The upper end of the passageway 19 in the valve body is internallythreaded to receive a plug 24 containing a metering orifice 25. Theupper end of the valve body which is threaded externally with a slighttaper, is threadably fitted into an opening in housing 26 for a horn 27.When the valve is open, the metering orifice 25 in the passageway 19controls the flow of gas or vapor under pressure into the housing andenables the signalling unit to operate properly over a wide range ofpressures in the cylinder. 7

The housing 26 has an opening at one end thereof in which a vibratablediaphragm 28 is located with its outer edges being held between a pairof spacing washers 29 and 30. The inner washer 30 is seated against ashoulder in the housing and an end cap 31 which is threadably fitted inthe open end of the housing bears against the outer washer 29. The endcap bears against the outer In .the case of dichlorodifluoromethanevwasher 29 which creates a space between the center of the end cap andthe diaphragm and this space is vented by a small drilled hole 32 in theend cap to permit the diaphragm to vibrate readily without damping. Thewashers also serve to seal the outer edges of the diaphragm effectivelyto the housing. The end cap has recesses 33 in its outer end to receivea spanner wrench which permits the cap to be tightened to form a sealand to hold the edges of the diaphragm firmly in place.

An important feature of the present invention is the discovery that adiaphragm type horn having a diaphragm less than 2 /2 inches in diametermay be operated by means of a gas of greater density than air,.such asdichlorofluoromethane, more commonly known as Freon- 12, at relativelylow pressures to produce an audible signal of satisfactory volume andpitch for use in a signalling device. Aspreviously mentioned,dichlorofiuoromethane is a suitable material for use in operating such adiaphragm type horn and in gas or vapor form, it has a density of5.4'grams per liter as compared with an average density of 1.25 gramsper liter for air. Another example of suitable gas is ,carbon dioxide(CO which has a density of 1.96 grams per liter. This not only permits adiaphragm type horn of a size small enough to be used in aself-contained portable signalling device to be constructed, but it alsoenables such a signalling device to be operated for a considerableperiod of time from a relatively small container in which a supply of avaporizable material is maintained in liquid form.

. In the example of the signalling device embodying the presentinvention which is illustrated and described herein, the diaphragm 28has an overall diameter of only one inch with the clear area between theinner edges of the washers 29 and 30 being of an inch in diameter.Despite the small size of this diaphragm, an audible signal having avolume of over 100 decibels is produced at a gas pressure of from 12 to15 pounds per square inch when the horn is operatedby a high density gassuch as dichlorodifiuoromethane. The diaphragm 28 may be made ofstainless steel or other suitable material and may vary in thicknessfrom one to three thousandths of an inch without materially affectingthe character of the signal produced.

It is significant to note that a diaphragm. horn of these dimensionscannot be operated by air under pressure to produce a satisfactorysignal and it has generally been considered impossible or impractical toconstruct a diaphragm type of horn for operation by air or steam having.a diaphragm less than 2 inches in diameter. Also,

in an air operated diaphragm type of horn, a minimum air pressure of 40pounds per square inch is required to obtain effective sound and, underthese conditions, it would obviously be impractical to make aself-contained portable signalling device using air as the source ofpower.

Thus, the discovery that a horn having a diaphragm of less than 2 /2inches in diameter will produce an audible signal of satisfactory volumeand pitch when operated by a gas having a density of approximately 1 /2to 4 times the density of air leads to unexpected results andadvantages. In the first place, it permits the use of a small horn whichin turn makes it possible to construct a small and lightweightsignalling device that can be carried about in the operators hand foroperation as desired. Further, the factthat such a horn will operatesatisfactorily at 'low pressure makes it possible to operate such a hornover a substantial period of time from a relatively small quantity ofvaporizable material.

The born 27 may be made in one piece and has a threaded section on itsouter surface which engages with a threaded opening in the other end ofthe housing making a tight fit therewith. Slots 34 are provided on theouter surface of the horn to receive a spanner wrench which may be usedto seat'the horn' in thehousing.

The inner end of the horn abuts the central portion of the diaphragm anddistends the diaphragm slightly. The

v V I distension of the diaphragm is such that when the gas or vaporunder pressure is admitted to the housing, the diaphragm is forcedrearwardly or away from the throat of the horn and permits the gaswithin the housing to escape through the horn. When the pressure of thegas within the housing drops sufliciently, the diaphragm returns to itsoriginal or closed position with the cycle of operation then beingrepeated and causing the diaphragm to vibrate. The vibration of thediaphragm in this manner acts on the column of escaping gas in the hornand sets up vibrations therein which produce the audible sound orsignal.

In the illustrated embodiment of the invention, the metering orifice 25is approximately .027 inch in diameter. However, it will be understoodthat the diameter of this opening may be varied without appreciablyaffecting the operation of the diaphragm or changing the tone of thehorn. The orifice regulates the consumption of the gas and reduces thepressure of the gas acting on the diaphragm to the pressure required forthe desired operation of the horn.

In Operation of the device, the valve 16 is opened by pressing on thelever 23. This permits gas under pressure emanating from the liquidmaterial in the cylinder to flow into the housing 26 at a controlledrate through the metering orifice 25 in the plug 24. The gas underpressure inthe housing causes the diaphragm to vibrate at anaudiblefrequency as the gas escapes through the born. The signal thusproduced has a volume of about to decibels and will be loud enough to beheard for a considerable distance. The duration of the signal can becontrolled at willby operation of the valve. In a raised position of thelever 23, the valve will remain open for a continuous signal and anintermittent signal may be produced by' depressing. the lever 28' andthen releasing it.

It will be understood that various changes and modifications may be madeinthe embodiment of the invention described and illustrated hereinwithout departing from the scope of the invention as defined by thefollowing claims.

I claim:

1. A self-powered, portable signalling. device comprising a container, asupply of vaporizable liquid in said container, said vaporizable liquidhaving a density when in vapor form up to four times the density of airand being vaporizable at atmospheric pressure at temperatures as low as20 F., a fitting removably connected to said container and having afirst conduit which communicates with the interior thereof, a housingconnected to said fitting, said fitting having a second conduit whichcommunicates with the interior of said housing, a manually operablevalve connected to and carried by said fitting, the conduits in saidfitting being adapted to communicate with each other upon the opening ofsaid manually operable valve, and a diaphragm-type horn carried by saidhousing and operatively communicating with said second conduit, thediaphragm of said diaphragmtype horn being substantially circular inshape and disposed in said housing, the diameter of said diaphragm beingless then two and one-half inches.

2. A self-powered, portable signalling device comprising a container, asupply of vaporizable liquid in said container, said vaporizable liquidhaving a density when in vapor form up to four times the density of airand being vaporizable at atmospheric pressure at temperatures as low as20 F., a fitting removably connected to said container and having afirst conduit which communicates with the interior thereof, a housingconnected to said fitting, said fitting having a second conduit whichcommunicates with the interior of said housing, a manually operablevalve connected to and carried by said fitting, the conduits insaidfitting being adapted to communicate with each other upon the opening ofsaid manually operable valve, a diaphragm-type horn carried by saidhousing and operatively communicating with said second conduit, thediaphragm of said diaphragm-type horn being substantially circular inshape and disposed in said housing, the diameter of said diaphragm beingless than two and one-half inches, and a metering device in said secondconduit.

3. A self-powered, portable signalling device comprising a container, asupply of liquid dichlorodifluoromethane in said container, a fittingremovably connected to said container and having a first conduit whichcommunicates with the interior thereof, a housing connected to saidfitting, said fitting having a second conduit communicating with theinterior of said housing, a manually operable valve connected to andcarried by said fitting, the conduits in said fitting being adapted tocommunicate with each other upon the opening of said manually operablevalve, and a diaphragm-type horn carried by said housing and operativelycommunicating with said second conduit, the diaphragm of saiddiaphragm-type horn being substantially circular in shape and disposedin said housing, the diameter of said diaphragm being less than two andonehalf inches.

References Cited in the file of this patent UNITED STATES PATENTS1,898,546 Kelley Feb. 21, 1933 2,778,330 Jacoby Jan. 22, 1957 2,793,651Gomez May 28, 1957

